Many Americans Suffering Silent MIs
(HealthDay News) — New research suggests that many Americans are suffering silent myocardial infarctions. The study appears in the Nov. 10 issue of the Journal of the American Medical Association, a cardiovascular disease theme issue published to coincide with the annual meeting of the American Heart Association, held from Nov. 7 to 11 in Orlando, Fla.
The study was led by David Bluemke, M.D., Ph.D., of the U.S. National Institute of Biomedical Imaging and Bioengineering in Bethesda, Md. His team reviewed data for 1,840 people, ages 45 to 84, from various ethnic groups who were free of cardiovascular disease when they enrolled in the study between 2000 and 2002. Ten years later, all the patients underwent cardiac magnetic resonance imaging to assess their cardiovascular health. Their average age at that time was 68.
The scans revealed that 7.9 percent of the participants had myocardial scars, 78 percent of which had previously gone undetected. Men were much more likely than women to have this type of scar, nearly 13 percent versus 2.5 percent. Other factors associated with a higher risk of myocardial scarring included smoking, higher body mass index, greater levels of coronary artery calcium, and the use of hypertensive medications at the start of the study.
The researchers stressed that a determination of the health impact of these silent attacks "remains to be defined." However, they pointed out that 70 percent of patients who lose their lives to sudden cardiac death show evidence of this type of prior myocardial scarring.